The Pedestrian and Bicyclist Intersection Safety Indices (ISI) Calculators that accompany this user manual are available in a Microsoft® Excel® spreadsheet format. Full functionality is only available in the Excel download. [Download pedestrian calculator HTML , Excel] [Download bicycle calculator HTML , Excel]

Pedestrian and Bicyclist Intersection Safety Indices

User Guide

FOREWARD

The primary objective of this study was to develop safety indices to allow engineers, planners, and other practitioners to proactively prioritize intersection crosswalks and intersection approaches with respect to pedestrian and bicycle safety. The models in this study use easily collected, observable characteristics of an intersection to produce safety index values. Practitioners will be able to use these models on a small or large scale to determine where best to focus efforts to improve pedestrian and bicyclist safety.

Michael Trentacoste, Director
Director, Office of Safety
Research and Development

Notice

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document.

The
U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document.

Quality Assurance Statement

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The primary objective of this study was to develop safety indices to allow engineers, planners, and other practitioners to proactively prioritize intersection
crosswalks and intersection approaches with respect to pedestrian and bicycle safety. The study involved collecting data on pedestrian and bicycle crashes,
conflicts, avoidance maneuvers, and subjective ratings of intersection video clips by pedestrian and bicycle experts. There were a total of 68 intersection
crosswalks selected for the pedestrian analysis from the cities of Philadelphia, PA; San Jose, CA; and Miami-Dade County, FL. The bicycle analysis included 67
intersection approaches from Gainesville, FL; Philadelphia, PA; and Portland and Eugene, OR.

Prioritization models were developed based on expert safety ratings and behavioral data. Indicative variables included in the pedestrian safety index model
included type of intersection control (signal or stop sign), number of through lanes, 85th percentile vehicle speed, main street traffic volume, and area type.
Indicative variables in the bicycle safety models (for through, right-turn, and left-turn bike movements) included various combinations of: presence of bicycle
lane, main and cross street traffic volumes, number of through lanes, presence of on-street parking, main street speed limit, presence of traffic signal, number
of turn lanes, and others. Through this User Guide, practitioners will be able to use the safety indices to identify which crosswalks and intersection
approaches have the highest priority for in-depth pedestrian and bicycle safety evaluations and subsequently use other tools to identify and address potential
safety problems.